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BitTorrent v2

blog.libtorrent.org

301–310 of 576 posts

Re: BitTorrent v2

#301
post #70

Earlier quoted context omitted.

You could have a protocol where every block of the file is actually two "random" blocks XOR'd together, but this doesn't really work. If you create a new 1GB torrent, you'll need 1GB of new (never seen before) blocks with ~100% probability, so it will be obvious who's seeding the data. Or you could make the block size smaller (e.g. 1 bit) and tell the lawyers to piss off because 0 and 1 are public domain.

> You could have a protocol where every block of the file is actually two "random" blocks XOR'd together One implementation of this is the "Owner-Free File System"[0], but it is no longer being maintained. > If you create a new 1GB torrent, you'll need 1GB of new (never seen before) blocks If you XOR your 1GB file (X) with 1GB of blocks that already exist on the system (Y), you get a new set of 1GB blocks (Z), but it…

Even if people aren't scraping the network to record the order of block creation, it will be mighty suspicious when the Y blocks are scattered randomly across the network, and the Z blocks are conveniently hosted in one place.

Re: BitTorrent v2

#303

Earlier quoted context omitted.

It was good design to decouple the transfer protocol from the search protocol, to allow different technologies to be explored, but in practice people ended up relying on the "good enough" solution of using the web for search. Setting the precedent that media companies can seize domain names and force ISPs to block access to search engines if they don't like some of the search results (while ruining the lives of the p…

Yes. For all the P2P distributed praise ITT, torrent as a whole, as it is used in the real world, is very centralized. If the Pirate Bay is shut down, that stuff is gone. Uploading became a privilege, something that normal average people don't do. Earlier people ripped their own CDs, DVDs, magazine scans, digitized their VHS, recorded shows with their TV card etc. and shared these files. I don't know anybody who has…

There must be 1000 Pirate Bay mirrors. Many of which served malware or scams on their web properties through ad networks, but faithfully reproduced the torrent database. It was centralization in precisely the way your post doesn't suggest: nothing was irrevocably lost but one wished for a trusted source with curated links to content.

Re: BitTorrent v2

#304

Earlier quoted context omitted.

This right here is the biggest new feature in my opinion, and should have been discussed in more depth in the announcement. I also think they should have pursued this avenue further before releasing v2. Content addressing is one of the big advantages of p2p applications, and IPFS has been pushing it for a long time. Just imagine if this was done all the way down to the piece level. You have two different torrents (sa…

>Just imagine if this was done all the way down to the piece level. I don't know about that. With a reasonably large number of users, wouldn't you start seeing hash collisions via birthday paradox? Might be better off keeping it at the file level. (Though this does incentivize malicious users to find hash collisions of particular files they want to defend, and seeding the swarm with garbage files)

the birthday paradox comes from the fact that there are an extremly small number of birthdays.

sha-256 was chosen because it provides a sufficiently high number of different hashes that this won't be an issue for the forseeable future.

more details here: https://stackoverflow.com/questions/4014090/is-it-safe-to-ig...

Re: BitTorrent v2

#305
post #257
post #208

Earlier quoted context omitted.

This is exactly the problem with all cryptocurrency currently. It’s a massive user experience issue, in the sense that users have to experience the technical bullshit of how the currencies work, completely missing the brilliant part of real money: it just works. I hand people money, they give me things. I swipe my credit card, I get things. I can’t remember who aid it originally, but there’s a great test you can give…

It has been a few years, and despite a few attempts, I still don't really understand bitcoin. Yes yes ledgers and proof of work and yada yada, but I still don't know what I would need to do to buy something with bitcoin right now. As I understand I need to do something that's pretty much exactly like opening a bank account, but transactions take forever, they cost money, and the currency is not accepted by any busine…

The problem as I see it that it is nothing like opening a bank account... You don’t need to understand the banking system to use a bank account. Meanwhile normal people without a serious networking/distributed systems background will not really grasp what they are doing when using bitcoin and have to resort to googling steps and following them blindly. The fact that ETH gas prices are going through the roof because of Defi would be a huge leak in the abstraction for something like a bank.

Re: BitTorrent v2

#306
What are people thoughts on transmission? I have never tried BitTorrent but I am curious to hear from others who might have tried both.

Re: BitTorrent v2

#307
post #58

Earlier quoted context omitted.

> It feels like this isn't a large enough leap forward. The hash it relies on is broken, so their hand has been forced.

sha1 is not meaningfully broken for BitTorrent, It would require a second pre-image attack to meaningfully hurt it, you can not take an existing hash you don't control and synthesize a matching set of incorrect/malicious data. Second preimage attacks are MUCH harder to pull off, even md5 is still safe from them, many years after they were found to be broken in other contexts. The only thing that sha1's weakness would…

The writing is on the wall, no need to wait for these attacks to actually exist before beginning migration

Re: BitTorrent v2

#308
post #274

Earlier quoted context omitted.

>As I understand I need to do something that's pretty much exactly like opening a bank account Not really. If I want a bank account I need to fill out a page of paperwork requiring my name, address, social security number, citizenship information, income, occupation, date of birth, scans of various pieces of ID and/or other documents. Compare this to bitcoin where you only need to install an app, and new identities c…

> It's true that trying to buy/sell bitcoins via an exchange will subject you to AML requirements, but in-person transactions won't. Nobody does bitcoin transactions in person, at least not in America and not anyone I know. I have several bitcoins and the only way to use them is through an exchange like coinbase, who require the same identity documents that a bank does. You could argue “but you just have to find vend…

>Nobody does bitcoin transactions in person, at least not in America and not anyone I know.

https://localbitcoins.com/

>You could argue “but you just have to find vendors who accept bitcoin!” But with 3 bitcoin I won’t find enough vendors to spend it on.

There are also bitcoin-for-gift-card stores, which vastly expands your vendor options.

Re: BitTorrent v2

#309

Earlier quoted context omitted.

>Just imagine if this was done all the way down to the piece level. I don't know about that. With a reasonably large number of users, wouldn't you start seeing hash collisions via birthday paradox? Might be better off keeping it at the file level. (Though this does incentivize malicious users to find hash collisions of particular files they want to defend, and seeding the swarm with garbage files)

Hashes are now 256 bits. In order to get a collision with probability 1% you need to produce about 4e37 hashes. For comparison, if you had a 5GHz computer that did a SHA-256 hash every cycle and gave 100 of these computers to every human on Earth, it'd take over 300 million years to produce 4e37 hashes.

Yep, basically while it's entirely possible (as per Murphy's Law) that there'll be an accidental collision, the likelihood is close to zero. It's a fair risk to be taking.

Re: BitTorrent v2

#310
post #227

Earlier quoted context omitted.

> sha1's weakness would require you to be the creator of the torrent Huh, why?

because you can create two hashes that match, but you cannot create a hash that matches an arbitrary hash you do not control. That is a much more serious weakness called a "second pre-image attack"

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